1. Field of the Invention
The invention relates to a system for recording an information signal on an optical readable record carrier, the recording being in the form of a pattern of recording marks having modified optical properties, which pattern represents the information signal. The recording apparatus comprises a control circuit for converting the information signal in conformity with a specific relationship into a series of consecutive write signals which form the consecutive recording marks having modified optical properties. As used herein, the term "optical" as applied to record carriers and properties thereof also includes magneto-optical record carriers having magneto-optical properties.
The invention further relates to a record carrier for use in the system.
2. Description of the Related Art
Such a system, record carrier and recording apparatus are known from U.S. Pat. No. 4,473,829, assigned to the present assignee, which is incorporated herein by reference.
In such known system the recording marks are formed by means of an optical write head which generates a laser beam which scans a recording layer of a radiation-sensitive material on the record carrier. To form recording marks the laser beam is modulated in conformity with write signals whose signal waveforms depend on the dimensions of the recording marks to be formed and the properties of the record-carrier material. The known system has the drawback that the write signals are optimized for recording on recording layers of "ablative" recording materials only, such a material being removed from the recording layer under the influence of the radiation energy supplied by means of the laser beam. However, when recordings are made on other types of radiation-sensitive recording layers, other write signal waveforms are preferable. As is described in the prior but non-prepublished Netherlands Patent Application No. 8602718 filed Oct. 29, 1986, which corresponds to U.S. Pat. No. 4,774,522, issued Sept. 27, 1988 on an application filed Mar. 12, 1987, assigned to the present assignee, which U.S. patent is incorporated herein by reference, the write signal waveforms required for making recordings on "phase-change" and "thermo-optical" materials are completely different than in the case of recording on "ablative" materials, as a result of specific thermal effects produced in the recording layer during recording. Moreover, the thermal effects for different materials of the same type also differ from each other, so that the optimum write signal waveforms for different materials of the same type may also be different.